Malaysian transportation officials took custody of the black boxes from downed Flight 17, and the Netherlands declared a day of mourning in preparation for the arrival of the first bodies from Ukraine.

The voice and data recorders were retrieved from the crash site controlled by pro-Russian rebels in eastern Ukraine, where the plane was shot down July 17 with a missile the U.S. says was probably supplied by Russia. The boxes will be passed to the U.K.’s Air Accident Investigations Board in Farnborough, Malaysia’s Transportation Ministry said in a statement.

Forensics work is accelerating as international pressure builds on Russian President Vladimir Putin to expedite a probe into who destroyed the Malaysian Air jet carrying 298 passengers and crew from Kuala Lumpur from Amsterdam. The European Union today threatened to restrict Russia’s access to capital markets and sensitive energy and defense technologies to squeeze its finances. Putin has said his opponents are using the crash for “selfish political gains.”

A train carrying 282 bodies and remains of other victims arrived in Kharkiv, Ukraine’s second-largest city, ending a four-day standoff with the separatists. At least 50 bodies will be ready for departure with the exact number to be moved tomorrow still to be determined, Ukrainian Deputy Prime Minister Volodymyr Hroisman told reporters. Preparations for the transfer to the Netherlands should be completed by July 25, he said.

“In the Netherlands we will identify the remains,” Jan Tuinder, a Dutch expert, told reporters. The Dutch government declared tomorrow to be a day of mourning.

An ‘outrage’

The International Air Transport Association on July 21 called the probe’s slow progress an “outrage to human decency.”

“The bodies of the victims must be returned to their grieving loved ones in a respectful manner,” IATA’s Director General Tony Tyler said in a statement. “For over four days we witnessed appalling sights from the crash scene. Governments must set aside their differences and treat the victims and their families with the dignity they deserve -- and this includes urgently securing the site.”

The smell of decaying bodies hovered over the crash site littered with burnt fuselage parts, about 300 kilometers (186 miles) south from Kharkiv. The perimeter was still protected by rebel gunmen today as international inspectors collected evidence for the investigation.

Crash scene

“It’s very important for us that all actions meet international laws,” Hroisman, the deputy prime minister, said in Kharkiv. If rebels hadn’t been involved, Ukraine would have “done all necessary procedures sooner.”

Control of the debris is emerging as a central issue in the aftermath of the tragedy. Investigators have said that a missile strike would leave telltale clues, which could help identify the weapon.

The Organization for Security and Co-operation in Europe noted some differences when observing the Boeing Co. 777’s fuselage compared with the first time its team saw the wreckage, Michael Bociurkiw, a spokesman for the delegation, told reporters today without elaborating.

One image of a heavily perforated piece of fuselage that appears to come from the plane’s cockpit suggests damage from a ground-fired warhead, analysts at IHS Jane’s said today.

“The punctures seen in the photograph are relatively uniform in size,” said Reed Foster, manager, military capabilities at IHS Jane’s. “This would potentially be consistent with a fragmentation-type warhead employed upon a number of modern and legacy surface-to-air missile systems.”

EU ultimatum

Russia already has been feeling the squeeze of international restrictions. The nation canceled its first ruble bond auction in three months after borrowing costs surged to the highest level in more than two months on the U.S. and EU criticism.

The Russian Finance Ministry, in a statement on its website, said it pulled tomorrow’s sale because of “unfavorable market conditions.”

EU governments paired their ultimatum with a decision to blacklist Russian businesspeople and companies for the first time, as Putin rejected allegations that Russian-backed rebels shot down the plane. The widened EU list will be announced on Thursday.

“We’re also ready to ready to introduce without delay a package of further significant restrictive measures if we don’t see full and immediate cooperation,” EU foreign policy chief Catherine Ashton told reporters after foreign ministers met today in Brussels.

UN resolution

EU governments would move toward the stiffer sanctions if Putin refuses to abide by a United Nations resolution calling for an international probe into the disaster and unimpeded access to the crash site. The timetable was left open, depending on proposals to be made by the European Commission, the bloc’s executive arm.

“Since the resolution we have seen a significant change in the cooperation from the rebels in this eastern Ukraine region,” Australian Foreign Minister Julie Bishop told Sky News television. As international pressure mounted “we saw a change in Russia’s attitude and President Putin for the first time called on the separatists to cooperate so that the investigation could get under way and the site be secured. This is what President Putin should have done from the outset.”